COSIN Résumé de rapport

Customization of visualization tools

The ability of drawing very large networks as e.g. large computer networks is of great significance in visualizing the evolution of stochastic models for evolving networks. One focuses on designing and implementing new algorithms and innovative software systems that display a large graph at different abstraction levels. For example, there is an increasing need of systems that show maps of the Web and support the user during her navigation, of systems that display and monitor the traffic on the Internet, and of systems that draw portions of the Internet as a graph. Until now, the vast majority of graph drawing algorithms that have been deeply studied and experimentally tested in the literature, like for instance for database schemes, can efficiently handle graphs of only hundreds of vertices. We aim at devising general algorithmic techniques for drawing large graphs and at experimenting their usage in new visualization systems, thus contributing to devising the technology transfer from the algorithmic research on graph drawing to its application in networks visualization. As part of this goal, we developed analysis-enhancing layouts and, in cooperation with Universite de Paris Sud, created a novel technique that preserves the readability of abstract visualizations while showing all elements. Further, combinations and extensions of well-known graph-drawing techniques have been adapted to cope with specific networks like the Autonomous System network.